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| author | Michael Wang <wangyun@linux.vnet.ibm.com> | 2012-09-20 08:51:06 +0800 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2012-11-08 11:50:17 -0800 |
| commit | 51d0f16d49f6a99189e80c50e18a12325664ef41 (patch) | |
| tree | 2d7e28e39eff3d1d169ccca95e18a0f06cc574af /kernel/rcutree_trace.c | |
| parent | d29200efa2ad7a1dc516a1048faf98dcc01b9fef (diff) | |
| download | lwn-51d0f16d49f6a99189e80c50e18a12325664ef41.tar.gz lwn-51d0f16d49f6a99189e80c50e18a12325664ef41.zip | |
rcu: Optimize the 'rcu_pending' for RCU trace
This patch implements the new 'rcu_pending' interface under each rsp
directory, by using the 'CPU units sequence reading', thus avoiding loss
of tracing data.
Signed-off-by: Michael Wang <wangyun@linux.vnet.ibm.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'kernel/rcutree_trace.c')
| -rw-r--r-- | kernel/rcutree_trace.c | 41 |
1 files changed, 35 insertions, 6 deletions
diff --git a/kernel/rcutree_trace.c b/kernel/rcutree_trace.c index e387a642632b..8b2486722211 100644 --- a/kernel/rcutree_trace.c +++ b/kernel/rcutree_trace.c @@ -467,6 +467,8 @@ static const struct file_operations rcugp_fops = { static void print_one_rcu_pending(struct seq_file *m, struct rcu_data *rdp) { + if (!rdp->beenonline) + return; seq_printf(m, "%3d%cnp=%ld ", rdp->cpu, cpu_is_offline(rdp->cpu) ? '!' : ' ', @@ -485,16 +487,12 @@ static void print_one_rcu_pending(struct seq_file *m, struct rcu_data *rdp) static int show_rcu_pending(struct seq_file *m, void *unused) { int cpu; - struct rcu_data *rdp; struct rcu_state *rsp; for_each_rcu_flavor(rsp) { seq_printf(m, "%s:\n", rsp->name); - for_each_possible_cpu(cpu) { - rdp = per_cpu_ptr(rsp->rda, cpu); - if (rdp->beenonline) - print_one_rcu_pending(m, rdp); - } + for_each_possible_cpu(cpu) + print_one_rcu_pending(m, per_cpu_ptr(rsp->rda, cpu)); } return 0; } @@ -512,6 +510,32 @@ static const struct file_operations rcu_pending_fops = { .release = single_release, }; +static int new_show_rcu_pending(struct seq_file *m, void *v) +{ + print_one_rcu_pending(m, (struct rcu_data *)v); + return 0; +} + +static const struct seq_operations new_rcu_pending_op = { + .start = r_start, + .next = r_next, + .stop = r_stop, + .show = new_show_rcu_pending, +}; + +static int new_rcu_pending_open(struct inode *inode, struct file *file) +{ + return r_open(inode, file, &new_rcu_pending_op); +} + +static const struct file_operations new_rcu_pending_fops = { + .owner = THIS_MODULE, + .open = new_rcu_pending_open, + .read = seq_read, + .llseek = no_llseek, + .release = seq_release, +}; + static int show_rcutorture(struct seq_file *m, void *unused) { seq_printf(m, "rcutorture test sequence: %lu %s\n", @@ -561,6 +585,11 @@ static int __init rcutree_trace_init(void) rspdir, rsp, &new_rcudata_csv_fops); if (!retval) goto free_out; + + retval = debugfs_create_file("rcu_pending", 0444, + rspdir, rsp, &new_rcu_pending_fops); + if (!retval) + goto free_out; } retval = debugfs_create_file("rcubarrier", 0444, rcudir, |